The Synthesis Of A New Halogen-Free Intumescent Flame Retardant And Its Application

Halogen-free intumescent flame retardants (IFR) are mainly composed of phosphorus and nitrogen,. IFR adding to Polypropylene (PP) may improve the material's flame retardancy performance, meanwhile suppress releasing of toxic-substance and gas. Nowdays, Synergistic flame-retarded effects during the acid source, the carbon source and the gas source of IFR system had been studied widely.One intumescent flame retardants (IFR) containing various orbicular phosphates melamme salts was synthesized from the carbon source(starch), the dehydration catalyst(phosphoric pentoxide, phosphoric acid and polyphosphoric acid), and the blowing agent(melamine)o The optimal conditions of reaction (reaction molar ratio, reaction temperature,and reaction time) were gained by the orthogonal experiment.The polypropylene (PP) added with the IFR showed the excellent flame retardancy. The experiment indicated the LOI to 31 5, the SDR less than 45. 0, and UL94V-0. The polypropylene (PP) added with the IFR has not only good self-extinguish effect but also non melt and dript phenomena. When burning, PP/IFR was swelled and formed char. DTA. The curves of TG and DSC showed that the IFR possessed excellent thermal stabilities and char-forming peculiarity.The structures of IFR, PP and PP added with IFR were analyzed by SEM and XRDo The SEM experiment indicated that the dispersion and the compatibility of IFR in PP was not perfected, The XRD experiment indicated that PP with IFR contains the same eight diffraction apex with PP. Although its intension was depressed, its flame retardancy was better, but its performance of mechanice was affected.